[Instrumentation.AspNetCore] Handle cases where the HttpContext is a property of the payload (ASP.NET Core 2.x support)

src/OpenTelemetry.Instrumentation.AspNetCore/CHANGELOG.md

@@ -2,6 +2,12 @@
 
 ## Unreleased
 
+* Fixed issue
+  [#5019](https://github.com/open-telemetry/opentelemetry-dotnet/issues/5019)
+  where metrics and traces were not exported for incoming requests when using
+  ASP.NET Core 2.x.
+  ([#2724](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/2724))
+
 ## 1.11.1
 
 Released 2025-Mar-05

src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInListener.cs

@@ -47,6 +47,7 @@ internal class HttpInListener : ListenerHandler
     };
 
     private static readonly PropertyFetcher<Exception> ExceptionPropertyFetcher = new("Exception");
+    private static readonly PropertyFetcher<HttpContext> HttpContextPropertyFetcher = new("HttpContext");
 
     private readonly AspNetCoreTraceInstrumentationOptions options;
 
@@ -102,8 +103,15 @@ public void OnStartActivity(Activity activity, object? payload)
 
         if (payload is not HttpContext context)
         {
-            AspNetCoreInstrumentationEventSource.Log.NullPayload(nameof(HttpInListener), nameof(this.OnStartActivity), activity.OperationName);
-            return;
+            if (TryFetchHttpContext(payload, out var innerContext))
+            {
+                context = innerContext;
+            }
+            else
+            {
+                AspNetCoreInstrumentationEventSource.Log.NullPayload(nameof(HttpInListener), nameof(this.OnStartActivity), activity.OperationName);
+                return;
+            }
         }
 
         // Ensure context extraction irrespective of sampling decision
@@ -237,8 +245,15 @@ public void OnStopActivity(Activity activity, object? payload)
         {
             if (payload is not HttpContext context)
             {
-                AspNetCoreInstrumentationEventSource.Log.NullPayload(nameof(HttpInListener), nameof(this.OnStopActivity), activity.OperationName);
-                return;
+                if (TryFetchHttpContext(payload, out var innerContext))
+                {
+                    context = innerContext;
+                }
+                else
+                {
+                    AspNetCoreInstrumentationEventSource.Log.NullPayload(nameof(HttpInListener), nameof(this.OnStopActivity), activity.OperationName);
+                    return;
+                }
             }
 
             var response = context.Response;
@@ -347,6 +362,12 @@ static bool TryFetchException(object? payload, [NotNullWhen(true)] out Exception
         }
     }
 
+#if NET
+    [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "The ASP.NET Core framework guarantees that top level properties are preserved")]
+#endif
+    private static bool TryFetchHttpContext(object? payload, [NotNullWhen(true)] out HttpContext? context)
+        => HttpContextPropertyFetcher.TryFetch(payload, out context) && context is not null;
+
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static bool TryGetGrpcMethod(Activity activity, [NotNullWhen(true)] out string? grpcMethod)
     {

src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInMetricsListener.cs

@@ -65,21 +65,21 @@ static bool TryFetchException(object? payload, [NotNullWhen(true)] out Exception
         {
             return ExceptionPropertyFetcher.TryFetch(payload, out exc) && exc != null;
         }
-#if NET
-        [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "The ASP.NET Core framework guarantees that top level properties are preserved")]
-#endif
-        static bool TryFetchHttpContext(object? payload, [NotNullWhen(true)] out HttpContext? ctx)
-        {
-            return HttpContextPropertyFetcher.TryFetch(payload, out ctx) && ctx != null;
-        }
     }
 
     public static void OnStopEventWritten(string name, object? payload)
     {
         if (payload is not HttpContext context)
         {
-            AspNetCoreInstrumentationEventSource.Log.NullPayload(nameof(HttpInMetricsListener), nameof(OnStopEventWritten), HttpServerRequestDurationMetricName);
-            return;
+            if (TryFetchHttpContext(payload, out var innerContext))
+            {
+                context = innerContext;
+            }
+            else
+            {
+                AspNetCoreInstrumentationEventSource.Log.NullPayload(nameof(HttpInMetricsListener), nameof(OnStopEventWritten), HttpServerRequestDurationMetricName);
+                return;
+            }
         }
 
         TagList tags = default;
@@ -133,4 +133,10 @@ public override void OnEventWritten(string name, object? payload)
                 break;
         }
     }
+
+#if NET
+    [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "The ASP.NET Core framework guarantees that top level properties are preserved")]
+#endif
+    private static bool TryFetchHttpContext(object? payload, [NotNullWhen(true)] out HttpContext? context)
+        => HttpContextPropertyFetcher.TryFetch(payload, out context) && context is not null;
 }